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					                                CDAAC status




COSMIC retreat October 2004   UCAR COSMIC Project Office
                                        CDAAC 1.0


                                                 •   Delivered on time to
                                                     NSPO
                                                 •   Two CDs including
                                                     over 120 source code
                                                     packages and 800
                                                     Megabytes of test data
                                                     for 3 satellite missions




COSMIC retreat October 2004   UCAR COSMIC Project Office
                              CDAAC 1.0 features

                                                 •   Completely re-written for
                                                     Bernese 5.0
                                                 •   Improved LEO orbit
                                                     computation
                                                 •   Post-processing now can be
                                                     spread to all nodes of a cluster
                                                 •   Improved statistical
                                                     optimization and error
                                                     characterization in
                                                     atmospheric inversions
                                                 •   Ionospheric processing added
                                                     to CHAMP and SAC-C
                                                     missions




COSMIC retreat October 2004   UCAR COSMIC Project Office
                              CDAAC 1.0 features (cont)

                                                   •   Automatic Ionosonde
                                                       comparisons
                                                   •   New 1D variational
                                                       assimilation for moisture
                                                       computation
                                                   •   Web-based operator
                                                       interface and configuration
                                                       editor
                                                   •   Extensive documentation
                                                       improvement
                                                   •   Bug fixes and code cleanup




COSMIC retreat October 2004     UCAR COSMIC Project Office
                              Missing from CDAAC 1.0

•   TIP instrument processing:
     • Level 1b radiance and pointing information file
     • Level 2 inversion (combined with RO)
     • Difficult to debug until we have real data
•   COSMIC level 0 to 1 code
•   Open Loop capability
•   Dual cluster functionality
•   Operator interface to payload SOH data
•   TBB processing capability




COSMIC retreat October 2004     UCAR COSMIC Project Office
                       POD and Excess Phase Status

                                Bill Schreiner
                                 Doug Hunt




COSMIC retreat October 2004   UCAR COSMIC Project Office
                         POD and Excess Phase

   •    GPS Satellite Orbits
        - gpsOrb5.pl completed
        - GPS orbits are held fixed to IGS Final and IGU UltraRapid (6-hr update)
          orbits throughout processing
   •    Ground Station Coordinate and Troposphere (ZTD) Estimates
        - fidTrop5.pl, estTrop.pl, estCoord.pl completed
   •    High-Rate GPS clock estimates
        - comClk5.pl completed
        - phase-derived clocks aligned to sum of IGS GPS clocks
   •    Post-Processed LEO Satellite POD
        - leoOrb5.pl completed
        - Processes zero-difference L3 phase observations with reduced-dynamic (via velocity
        pulses) strategy (No ambiguity resolution)
   •    Near Real-Time LEO Satellite POD
        - leoOrb5rt.pl completed
        - high-rate GPS clocks solved for throughout LEO arc
   •    Documentation of POD algorithms completed


COSMIC retreat October 2004      UCAR COSMIC Project Office
                              POD and Excess Phase (cont)

     •   Excess Phase Generation
         - processOcc5.pl completed
           - computes atmospheric excess phase delay via double-differencing
           - computes biased ionospheric TEC via (L1-L2) processing
           - modified to process Open-Loop data


    Tasks to be completed
    •  POD
       - Analyze orbit quality for all missions, optimize reduced-dynamic tracking
       - Investigate simultaneous use of data from 2 POD antennas
    •  Excess Phase
       - Test single-difference and zero-difference (GRACE-USO) processing
       - correct cycle slips in non-occulting links
       - modify software to process data with short gaps in non-occulting links
       - Complete documentation and algorithm description




COSMIC retreat October 2004        UCAR COSMIC Project Office
                 Post-Processed CHAMP Orbit Overlap vs.
                                  JPL


                                   Daily 24 hour arcs
                      Position                                Velocity




COSMIC retreat October 2004      UCAR COSMIC Project Office
                      Near Real Time CHAMP Orbit Overlap



                              Arcs for every CHAMP data dump

                   Position                                     Velocity




COSMIC retreat October 2004        UCAR COSMIC Project Office
      Radio Occultation Sensor Evaluation (ROSE) -
            GFZ/JPL/UCAR Inter-comparison
              (extracted from Jens Wickert presentation at NCAR Summer Colloquium - 2004)




COSMIC retreat October 2004        UCAR COSMIC Project Office
COSMIC retreat October 2004   UCAR COSMIC Project Office
COSMIC retreat October 2004   UCAR COSMIC Project Office
COSMIC retreat October 2004   UCAR COSMIC Project Office
COSMIC retreat October 2004   UCAR COSMIC Project Office
                       1D VAR moisture assimilation

                               Tae-Kwon Wee




COSMIC retreat October 2004   UCAR COSMIC Project Office
                     1D-Var Retrieval Scheme

                                              •   1D-Var method now used
                                                  replacing previous statistical
                                                  retrieval code (simret)
                                              •   Initial tests show high stability
                                                  of algorithm and realistic
                                                  statistics
                                              •   Further work is necessary to
                                                  settle on optimal configuration
                                                  parameters and covariance
                                                  matrices
                                              •   Documentation available
                                                  online




COSMIC retreat October 2004   UCAR COSMIC Project Office
                              Ionospheric Data Products

                                  Stig Syndergaard
                                    Bill Schreiner




COSMIC retreat October 2004       UCAR COSMIC Project Office
                     Ionospheric data products
     CDAAC plans to provide the following ionospheric data
      products

     ●   GPS receiver
          ●   Absolute Total Electron Content (TEC) to all GPS satellites in view at all
              times
          ●   Occultation TEC and derived electron density profiles


     ●   Tiny Ionospheric Photometer (TIP)
          ●   Nadir intensity on the night-side from radiative recombination emission at
              1356 Å
          ●   Derived F-layer peak density and critical frequency
          ●   Location and intensity of ionospheric anomalous structures


     ●   Tri-Band beacon
          ●   Phase and amplitude of radio signals at 150, 400, and 1067 MHz
          ●   TEC between the COSMIC satellites and ground receivers
COSMIC retreat October 2004      UCAR COSMIC Project Office
                              Ionospheric occultation data processing –
                                            CDAAC 1.0


 ●   CHAMP electron
     density profiles

 ●   Compared with in
     situ electron density
     from CHAMP
     Langmuir Probe (+)




      ●   Currently looking into bias to Langmuir Probe data
      ●   Work to be done on combining RO data with other
          data types
COSMIC retreat October 2004       UCAR COSMIC Project Office
                        Combination with TIP and Global Ionospheric
                                       Maps (GIMs)


 ●   TIP provides valuable
     information about
     horizontal gradients
     along the subsatellite
     track



                                                    ●   GIMs (derived from
                                                        ground-based GPS)
                                                        provide global
                                                        information about
                                                        horizontal gradients
COSMIC retreat October 2004    UCAR COSMIC Project Office
                              Open Loop data status

                               Sergey Sokolovskiy
                                  Bill Schreiner
                                   Doug Hunt




COSMIC retreat October 2004     UCAR COSMIC Project Office
            Preparing for open-loop (OL) tracking of L1
               tropospheric RO signals in COSMIC

       Advantage: free of tracking errors.
       Advantage: acquisition of rising occultations.
       Disadvantage: generally, lower SNR.

       Due to limited bandwidth in LEO, OL tracking needs Doppler model.

       RO signal is acquired and transmitted to the ground with un-removed
       data modulation (must be removed in post-processing).

       JPL started acquisition of the OL setting occultations on SAC-C.
       The data are forwarded to CDAAC for analysis and feedback.
       CDAAC is exploring different options for removal of data modulation.


COSMIC retreat October 2004    UCAR COSMIC Project Office
          Validation of the “receiver-running” Doppler model against more
          accurate “computer-running” model based on N-climatology,
          in general, shows good agreement. Some things (2-3Hz offset at
          PLL-OL transition and >5Hz deviation at HSL<-100km)
          are suggested for the future improvement.




COSMIC retreat October 2004   UCAR COSMIC Project Office
                                                                            Q
         Strong atmospheric modulation and noise                                ui
         do not allow to clearly distinguish the data         delta phase
         bits in acquired signal (this, in part, must                                I
         be the reason for PLL tracking errors).                  ui+1


                 the samples likely
                 Affected by data bits


                                         ?
                 the samples likely
                 not affected by data bits




COSMIC retreat October 2004      UCAR COSMIC Project Office
           An example of retrieval of the SAC-C OL data (lat=23o) with ad hoc
           removal of data modulation based on magnitude of the phase lapse




COSMIC retreat October 2004   UCAR COSMIC Project Office
          Currently, statistics of the SAC-C OL retrievals are not as good as PLL.

          This can be related to incomplete removal of data modulation in
          the post-processing (currently using ad hoc method based solely
          on the phase lapse).

          CDAAC is looking into possibility of independently obtaining data
          bit stream from all GPS satellites by ground receivers for complete
          data demodulation in the post-processing
          (“Open Source GPS Software”).

          Concern: rising occultations on SAC-C are not acquired yet.




COSMIC retreat October 2004    UCAR COSMIC Project Office
                        CDAAC operational concerns

                                  Doug Hunt
                                  Karl Hudnut
                              Maggie Sleziak-Sallee




COSMIC retreat October 2004     UCAR COSMIC Project Office
                              CDAAC preparation for launch

 •   For launch in late 2005, we will need to sort out:
      • Complete reprocessing with CDAAC 1.0 code

      • Dual cluster software issues

      • Purchasing of production clusters and I/O machines

      • I/O machine replacement issues

      • Show and tell display

      • Fiducial network development

      • Porting CDAAC to 64 bit machines

      • Final archival policies

      • Processing other missions, such as GRACE

      • Other items?




COSMIC retreat October 2004     UCAR COSMIC Project Office
                                  Dual string processing
                                                                    Scp
                                                                 forwarding       TACC
         Data sources:             FTP
      USN, CDDIS, JPL,                                  I/O
            etc                                                          Web or FTP
                                                      machine
                                                                                         Other data
                              Scp forwarding                                               users
                                                NFS mount,       Scp forwarding

                                               Postgres client

                                Cluster 1            Previous
                                                     day rsync       Cluster 2
                                (primary)




                                                   UCAR security
                                                     perimeter




COSMIC retreat October 2004      UCAR COSMIC Project Office
                              Computer Room Requirements

                                                              •    Need 2 new Beowulf
                                                                   Clusters for dual string
                                                                   CDAAC
                                                              •    Beowulf Clusters and
                                                                   racks require
                                                                  2.5’ x 4’ x 6.2’ (width x
                                                                   length x height)
                                                              •    Beowulf Clusters and
                                                                   racks consume approx.
                                                                   3 kW and dissipate heat
                                                                   at approx. 9000
                                                                   BTU/Hr
                                                              •    Total power con-
                                                                   sumption: 21.5 kW.
                                                              •    Total heat dissipation:
                                                                   64,500 BTU/Hr.



COSMIC retreat October 2004      UCAR COSMIC Project Office
                              Show and Tell Display
    • A large monitor will be hung in the entryway
      of the FL4 COSMIC offices
    • This will show a continuous display of
      COSMIC data recently processed
    • An application which displays COSMIC data
      in a cool way needs to be developed
    • Initial ideas:
       – A very high resolution flat-panel monitor
           attached to a fast PC running a web
           browser
       – A special URL on the I/O machine’s web
           server which would display several
           animated Earth images, one for each
           COSMIC satellite
           (see www.cosmic.ucar.edu/champ.html)
       – Other ideas?



COSMIC retreat October 2004   UCAR COSMIC Project Office
                                 Fiducial Network
 •   Current plans for COSMIC real time fiducial data
      • Get 15 minute, 1 second igsHrf data from CDDIS

      • Supplement this with streaming data from NR CAN

        (canHrf)
      • Finally, add several stations set up by COSMIC in

        the South Pacific, Brazil and perhaps other places
        (cosHrf)
      • Software in place to convert these data types to

        level1a (fidGps and f30Gps)




COSMIC retreat October 2004   UCAR COSMIC Project Office
                                       Lots to do…




COSMIC retreat October 2004   UCAR COSMIC Project Office

				
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